For example, International Patent Application No. WO02/12747 by the same Applicant shows a multiple layer pad for a disc brake in which the support plate of the friction material is made on two layers, or levels, which are integrated into a single rigid plate body, obtained by molding.
Such a solution allows the friction material to be firmly anchored to the support plate due to the addition of mass in the form of a layer buried in the friction material of the pad under conditions of use.
Document U.S. Pat. No. 3,490,563A discloses a multiple layer pad in which an opening is obtained in all layers of the support plate of the friction material, and the thrust force exerted e.g. by a piston is distributed by means of the edges of such openings which are not aligned with one another.
Document U.S. Pat. No. 4,103,761A discloses a multiple layer pad which comprises a multiple layer support plate, and such layers of the plate are connected to one another by means of welding points.
Such a solution allows the relative sliding of the layers forming the plate, which may therefore vibrate in independent manner from one another, thus dampening the vibrations.
Document U.S. Pat. No. 6,405,840B1 discloses a multiple layer pad comprising a meshed or netted metallic layer for reinforcing the structure of the support plate of the friction material.
The solution described above allows the friction material to flow inside the holes of the metal mesh or net, thus improving the coupling of the friction material to the plate.
Although such solutions are advantageous, they do not completely meet the contrasting needs of obtaining a multiple layer pad comprising a support plate of the friction material capable of dampening the vibrations, firmly anchoring to the friction material and being compatible with disc brake calliper products which precede the invention and already on the market.